Systems, devices, and methods to compensate for temperature effects on sensors
This document discusses, among other things, systems and methods to compensate for the effects of temperature on sensors, such as analyte sensor. An example method may include determining a temperature-compensated glucose concentration level by receiving a temperature signal indicative of a temperature parameter of an external component, receiving a glucose signal indicative of an in vivo glucose concentration level, and determining a compensated glucose concentration level based on the glucose signal, the temperature signal, and a delay parameter.
1. A temperature-compensated glucose sensor system comprising:
a glucose sensor circuit comprising a glucose sensor, the glucose sensor circuit configured to generate a glucose signal representative of a glucose concentration level;
a temperature sensor circuit comprising a temperature sensor, the temperature sensor circuit configured to generate a temperature signal indicative of a temperature parameter; and
a processor configured to determine:
a delay parameter, wherein the delay parameter is configured to account for a delay between a temperature change at the temperature sensor and a corresponding temperature change at the glucose sensor,
an estimated subcutaneous temperature parameter, wherein the estimated subcutaneous temperature parameter is calculated based on the temperature signal and the delay parameter, and
a compensated glucose concentration level based on the glucose signal and the estimated subcutaneous temperature.
2. The temperature-compensated glucose sensor system of claim 1 , wherein the temperature parameter is a temperature, a temperature change, or a temperature offset.
3. The temperature-compensated glucose sensor system of claim 1 , wherein the delay parameter includes a delay time period.
4. The temperature-compensated glucose sensor system of claim 3 , wherein the processor adjusts the delay time period based upon a temperature rate of change determined using the temperature parameter.
5. The temperature-compensated glucose sensor system of claim 1 , wherein the processor is configured to:
determine a condition, and
adjust the delay parameter based upon the condition.
6. The temperature-compensated glucose sensor system of claim 5 wherein the condition is one or more of: a change in temperature, a location, a geographic characteristic, or a physiologic information.
7. The temperature-compensated glucose sensor system of claim 5 wherein the processor determines the condition based on a signal from the glucose sensor.
8. The temperature-compensated glucose sensor system of claim 5 wherein the processor determines the condition based on a signal from the temperature sensor.
9. The temperature-compensated glucose sensor system of claim 5 wherein the processor determines the condition based on a signal from a third sensor, the third sensor being different from the glucose sensor or the temperature sensor.
10. The temperature-compensated glucose sensor system of claim 9 wherein the third sensor is one or more of: an accelerometer, a heart rate sensor, or a respiration sensor.
11. The temperature-compensated glucose sensor system of claim 1 , wherein the processor executes instructions to receive the glucose signal and the temperature signal and apply the delay parameter to determine the compensated glucose concentration level.
12. The temperature-compensated glucose sensor system of claim 1 , further comprising a memory circuit, wherein the system stores a value corresponding to the temperature parameter in the memory circuit, and the processor later retrieves the stored value from memory for use in determining the compensated glucose concentration level.
13. The temperature-compensated glucose sensor system of claim 1 , wherein the glucose sensor circuit includes an electrode operatively coupled to electronic circuitry configured to generate the glucose signal and a membrane over at least a portion of the electrode, the membrane including an enzyme configured to catalyze a reaction of glucose and oxygen from a biological fluid in contact with the membrane in vivo.
14. The temperature-compensated glucose sensor system of claim 1 wherein the delay parameter is a constant.
15. The temperature-compensated glucose sensor system of claim 1 wherein the delay parameter is variable based on temperature.
16. The temperature-compensated glucose sensor system of claim 1 wherein the delay parameter is variable based on information determined about a user of the temperature-compensated glucose sensor system.
17. The temperature-compensated glucose sensor system of claim 1 wherein the delay parameter is variable.